Local area networks (LAN's) have historically consisted of nodes interconnected by physical telecommunications media (e.g. coaxial cable, twisted pair wire or fibre optics).
Recently wireless LAN's, the nodes of which are not connected by means of a physical medium, have started to appear in the art. These wireless LAN's communicate by means of an infrared (IR), radio or other signals. One of the benefits of using wireless LAN's is that cabling is not required. This is particularly useful for mobile nodes such as laptop and notebook computers, PDA's (Personal Digital Assistant), and the like. If appropriately equipped with a suitable wireless adapter (which includes a transmitter/receiver and control card), such as an IR wireless adapter, the mobile nodes can move around and remain connected to the network, provided they do not move out of range for the IR adapter.
To accomplish a simultaneous three-way connection between a notebook PC, a desktop PC and a LAN, there are two possible approaches. The first approach involves using a router. The Network Operating System (NOS) of the desktop PC is provided with a built-in router program and connected to the Network Operating System (NOS) on the LAN. The NOS of the notebook PC is connected to the router within the desktop PC NOS. Data in the form of information packets from the NOS of the notebook PC destined for either the NOS of the desktop PC or the NOS's on the LAN is first received by the router program on the NOS of the desktop PC. Based on the destination information contained in the data packet, the router will either send the data packet to the NOS of the desktop PC or to NOS's on the LAN.
The second approach is that of the present invention and involves using a three-way bridge. The NOS of the desktop PC is directly connected to the three-way bridge program on the desktop PC. The NOS of the notebook PC is directly connected to the same three-way bridge program. The NOS's on the LAN are also directly connected to the same three-way bridge program.
The main difference between the router and the three-way bridge is that the router redirects data in the OSI (Open System Interconnection Standard) layer 3, i.e. the network layer, and the three-way bridge redirects data in the OSI layer 2, i.e. the data link layer.
The three-way bridge is preferred in a specific environment having only one notebook PC, one desktop PC, and a LAN. The three-way bridge is preferred over a router due to its simplicity in setting up the connections, operation by the end-use, and the ease of implementation.